Process cartridge, assembling method for process cartridge and grounding member

Abstract

A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, includes a cartridge frame; an electrophotographic photosensitive drum having a cylinder and a photosensitive layer thereon; process device actable on the photosensitive drum; a drum shaft for rotatably supporting the photosensitive drum on the cartridge frame, the drum shaft extending through the photosensitive drum; a grounding member for electrically grounding the photosensitive drum, the grounding member having a cylinder contacting portion contacted to an inside of the cylinder and a drum shaft contact portion having an inclined portion for contact with the drum shaft in a direction of insertion of the drum shaft into the photosensitive drum.

What is claimed is: 
     
       1. A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, comprising: a cartridge frame;   an electrophotographic photosensitive drum having a cylinder and a photosensitive layer thereon;   process means actable on said photosensitive drum;   a drum shaft for rotatably supporting said photosensitive drum on said cartridge frame, said drum shaft extending through said photosensitive drum; and   a grounding member for electrically grounding said photosensitive drum, said grounding member having a base, a cylinder contacting portion contacted to an inside of said cylinder, and a drum shaft contact portion having an inclined portion for contact with an outer circumferential surface of said drum shaft in a direction of insertion of said drum shaft into said photosensitive drum, wherein said inclined portion is supported by a protruding portion protruding from said base so as to be spaced from a surface of said base, and said inclined portion presses on the outer circumferential surface of said drum shaft, wherein said inclined portion is inclined toward the inserting direction of said drum shaft, wherein the included portion has a first bent portion and a second bent portion so as to be contacted at a plurality of positions of the outer circumferential surface of the drum shaft, and the first and second bent portions are contacted to the outer circumferential surface of the drum shaft at longitudinally different positions.   
     
     
       2. A cartridge according to claim 1, wherein said photosensitive drum is provided at one longitudinal end with a spur gear which functions to transmit driving force to a transfer roller of the main assembly when said process cartridge is mounted to the main assembly, and wherein said grounding member is mounted on said spur gear. 
     
     
       3. A cartridge according to claim 2, wherein said grounding member is positioned on the spur gear by engagement between a positioning hole formed in said grounding member and a projection provided on an engaging portion of the spur gear. 
     
     
       4. A cartridge according to claim 2, wherein said photosensitive drum is provided at the other end with a helical gear which functions to receive driving force for rotating a developing roller as said process means from the main assembly when said process cartridge is mounted to the main assembly, and also functions to transmit the driving force to the developing roller. 
     
     
       5. A cartridge according to claim 1, wherein said grounding member is of metal. 
     
     
       6. A cartridge according to claim 5, wherein said grounding member is of phosphor bronze. 
     
     
       7. A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, comprising: a cartridge frame;   an electrophotographic photosensitive drum having a cylinder and a photosensitive layer thereon;   process means actable on said photosensitive drum;   a drum shaft for rotatably supporting said photosensitive drum on said cartridge frame, said drum shaft extending through said photosensitive drum; and   a grounding member for electrically grounding said photosensitive drum, said grounding member having a base, a cylinder contacting portion contacted to an inside of said cylinder, and a drum shaft contact portion having a first contact portion and a second contact portion for contacting the outer circumferential surface of said drum shaft at longitudinally different positions, wherein said first and second contact portions are each supported by a protruding portion protruding from said base so as to be spaced from a surface of said base, and said first and second contact portions press on the outer circumferential surface of said drum shaft.   
     
     
       8. A cartridge according to claim 7, wherein said inclined portion is inclined toward the inserting direction of the drum shaft. 
     
     
       9. A cartridge according to claim 7, wherein said cylinder contacting portion has forked end having two branches which are contacted to the cylinder. 
     
     
       10. A cartridge according to claim 7, 8 or 9, wherein said photosensitive drum is provided at one longitudinal end with a spur gear which functions to transmit driving force to a transfer roller of the main assembly when said process cartridge is mounted to the main assembly, and wherein said grounding member is mounted on said spur gear. 
     
     
       11. A cartridge according to claim 10, wherein said grounding member is positioned on the spur gear by engagement between a positioning hole formed in said grounding member and a projection provided on an engaging portion of the spur gear. 
     
     
       12. A cartridge according to claim 10, wherein said photosensitive drum is provided at the other end with a helical gear which functions to receive driving force for rotating a developing roller as said process means from the main assembly when said process cartridge is mounted to the main assembly, and also functions to transmit the driving force to the developing roller. 
     
     
       13. A cartridge according to claim 9, wherein said grounding member is of metal. 
     
     
       14. A cartridge according to claim 13, wherein said grounding member is of phosphor bronze. 
     
     
       15. A cartridge according to claim 7, wherein said process cartridge includes the photosensitive drum and at least one of charging means, developing means and cleaning means, as said process means, which are unified into a cartridge detachably mountable relative to the main assembly. 
     
     
       16. A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, comprising: a cartridge frame;   an electrophotographic photosensitive drum having a cylinder and a photosensitive layer thereon;   a charging device for charging said photosensitive drum;   a developing member for developing a latent image formed on said photosensitive drum;   a cleaning device for removing residual toner from said photosensitive drum;   a cleaning frame for supporting said photosensitive drum, charging device and cleaning device;   a development frame for supporting said developing member and having a toner accommodating portion for accommodating toner to be used by said developing member, wherein said development frame and said cleaning frame are coupled with each other for relative rotation therebetween;   a drum shaft for rotatable supporting said photosensitive drum on said cleaning frame, said drum shaft extending through said photosensitive drum,   wherein said photosensitive drum is provided at one longitudinal end with a spur gear which functions to transmit driving force to a transfer roller of the main assembly when said process cartridge is mounted to the main assembly,   wherein said photosensitive drum is provided at the other end with a helical gear which functions to receive driving force for rotating a developing roller as said process means from the main assembly when said process cartridge is mounted to the main assembly, and also functions to transmit the driving force to the developing roller; and   a grounding member of metal material for electrically grounding said photosensitive drum, said grounding member having a base, a cylinder contacting portion contacted to an inside of said cylinder, and a drum shaft contact portion having an inclined portion for contact with said drum shaft in a direction of insertion of said drum shaft into said photosensitive drum, wherein said grounding member is mounted on said spur gear, wherein said inclined portion is supported by a protruding portion protruding from said base so as to be spaced from a surface of said base, and said inclined portion presses on the outer circumferential surface of said drum shaft, wherein the included portion has a first bent portion and a second bent portion so as to be contacted at a plurality of positions of the outer circumferential surface of the drum shaft, and the first and second bent portions are contacted to the outer circumferential surface of the drum shaft at longitudinally different positions.   
     
     
       17. A cartridge according to claim 16, wherein said grounding member is positioned on the spur gear by engagement between a positioning hole formed in said grounding member and a projection provided on an engaging portion of the spur gear. 
     
     
       18. A cartridge according to claim 16, wherein the metal is of phosphor bronze. 
     
     
       19. A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, comprising: a cartridge frame;   an electrophotographic photosensitive drum having a cylinder and a photosensitive layer thereon;   a charging member for charging said photosensitive drum;   a developing member for developing a latent image formed on said photosensitive drum;   a cleaning device for removing residual toner from said photosensitive drum;   a cleaning frame for supporting said photosensitive drum, charging device and cleaning device;   a development frame for supporting said developing member and having a toner accommodating portion for accommodating toner to be used by said developing member, wherein said development frame and said cleaning frame are coupled with each other for relative rotation therebetween;   a drum shaft for rotatably supporting said photosensitive drum on said cleaning frame, said drum shaft extending through said photosensitive drum,   wherein said photosensitive drum is provided at one longitudinal end with a spur gear which functions to transmit driving force to a transfer roller of the main assembly when said process cartridge is mounted to the main assembly,   wherein said photosensitive drum is provided at the other end with a helical gear which functions to receive driving force for rotating a developing roller as said process means from the main assembly when said process cartridge is mounted to the main assembly, and also functions to transmit the driving force to the developing roller; and   a grounding member of metal material for electrically grounding said photosensitive drum, said grounding member having a base, a cylinder contacting portion contacted to an inside of said cylinder, and a drum shaft contact portion having a first contact portion and a second contact portion for contacting the outer circumferential surface of said drum shaft at longitudinally different positions, and wherein said grounding member is mounted on said spur gear, and wherein said first and second contact portions are each supported by a protruding portion protruding from said base so as to be spaced from a surface of said base, and said first and second contact portions are press-contacted to the outer circumferential surface of the drum shaft.   
     
     
       20. A cartridge according to claim 19, wherein said first contact portion and second contact portion are inclined toward an inserting direction of said drum shaft into said photosensitive drum. 
     
     
       21. A cartridge according to claim 19, wherein said cylinder contacting portion has forked end having two branches which are contacted to the cylinder. 
     
     
       22. A cartridge according to claim 19, wherein said grounding member is positioned on the spur gear by engagement between a positioning hole formed in said grounding member and a projection provided on an engaging portion of the spur gear. 
     
     
       23. A cartridge according to claim 19, wherein the metal is of phosphor bronze. 
     
     
       24. A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, comprising: a cartridge frame;   an electrophotographic photosensitive drum having a cylinder and a photosensitive layer thereon;   a charging device for charging said photosensitive drum;   a developing member for developing a latent image formed on said photosensitive drum;   a cleaning device for removing residual toner from said photosensitive drum;   a cleaning frame for supporting said photosensitive drum, charging device and cleaning device;   a development frame for supporting said developing member and having a toner accommodating portion for accommodating toner to be used by said developing member, wherein said development frame and said cleaning frame are coupled with each other for relative rotation therebetween;   a drum shaft for rotatably supporting said photosensitive drum on said cleaning frame, said drum shaft extending through said photosensitive drum,   wherein said photosensitive drum is provided at one longitudinal end with a spur gear which functions to transmit driving force to a transfer roller of the main assembly when said process cartridge is mounted to the main assembly,   wherein said photosensitive drum is provided at the other end with a helical gear which functions to receive driving force for rotating a developing roller as said process means from the main assembly when said process cartridge is mounted to the main assembly, and also functions to transmit the driving force to the developing roller; and   a grounding member of metal material for electrically grounding said photosensitive drum, said grounding member having a base, a cylinder contacting portion contacted to an inside of said cylinder, and a drum shaft contact portion having a first contact portion and a second contact portion for contacting the outer circumferential surface of said drum shaft at longitudinally different positions, wherein said first contact portion and second contact portion are inclined toward an inserting direction of said drum shaft into said photosensitive drum, and wherein said grounding member is mounted on said spur gear, and wherein said first and second contact portions are each supported by a protruding portion protruding from said base so as to be spaced from a surface of said base, and said first and second contact portions are press-contacted to the outer circumferential surface of the drum shaft.   
     
     
       25. A cartridge according to claim 24, wherein said cylinder contacting portion has forked end having two branches which are contacted to the cylinder. 
     
     
       26. A cartridge according to claim 24, wherein said grounding member is positioned on the spur gear by engagement between a positioning hole formed in said grounding member and a projection provided on an engaging portion of the spur gear. 
     
     
       27. A cartridge according to claim 24, 25 or 26, wherein the metal is of phosphor bronze. 
     
     
       28. A grounding member usable for a process cartridge detachably mountable relative to an electrophotographic image forming apparatus, said process cartridge including: a cartridge frame;   an electrophotographic photosensitive drum having a cylinder and a photosensitive layer thereon;   a charging device for charging said photosensitive drum;   a developing member for developing a latent image formed on said photosensitive drum;   a cleaning device for removing residual toner from said photosensitive drum;   a cleaning frame for supporting said photosensitive drum, charging device and cleaning device;   a development frame for supporting said developing member and having a toner accommodating portion for accommodating toner to be used by said developing member, wherein said development frame and said cleaning frame are coupled with each other for relative rotation therebetween; and   a drum shaft for rotatably supporting said photosensitive drum on said cleaning frame, said drum shaft extending through said photosensitive drum,   wherein said photosensitive drum is provided at one longitudinal end with a spur gear which functions to transmit driving force to a transfer roller of the main assembly when said process cartridge is mounted to the main assembly,   wherein said photosensitive drum is provided at the other end with a helical gear which functions to receive driving force for rotating a developing roller as said process means from the main assembly when said process cartridge is mounted to the main assembly, and also functions to transmit the driving force to the developing roller;   said grounding member functioning to electrically ground said photosensitive drum, and said grounding member including: a base;   a cylinder contacting portion contacted to an inside of said cylinder when said grounding member is mounted to said process cartridge;   a through hole for permitting penetration of said drum shaft when said grounding member is mounted to said process cartridge; and   a drum shaft contact portion having an inclined portion for contact with an outer circumferential surface of said drum shaft in a direction of insertion of said drum shaft into said photosensitive drum when said grounding member is mounted to said process cartridge, wherein said inclined portion is supported by a protruding portion protruding from said base so as to be spaced from a surface of said base, and said inclined portion presses on the outer circumferential surface of said drum shaft, wherein said drum shaft contact portion has a plurality of such included portions, which are contacted to said drum shaft at longitudinally different positions.     
     
     
       29. A member according to claim 28, wherein said cylinder contacting portion has forked end having two branches which are contacted to the cylinder. 
     
     
       30. A member according to claim 28, wherein said grounding member is of metal. 
     
     
       31. A member according to claim 30, wherein said metal is phosphor bronze. 
     
     
       32. A grounding member usable for a process cartridge detachably mountable relative to an electrophotographic image forming apparatus, said process cartridge including: a cartridge frame;   an electrophotographic photosensitive drum having a cylinder and a photosensitive layer thereon;   a charging device for charging said photosensitive drum;   a developing member for developing a latent image formed on said photosensitive drum;   a cleaning device for removing residual toner from said photosensitive drum;   a cleaning frame for supporting said photosensitive drum, charging device and cleaning device;   a development frame for supporting said developing member and having a toner accommodating portion for accommodating toner to be used by said developing member, wherein said development frame and said cleaning frame are coupled with each other for relative rotation therebetween; and   a drum shaft for rotatably supporting said photosensitive drum on said cleaning frame, said drum shaft extending through said photosensitive drum,   wherein said photosensitive drum is provided at one longitudinal end with a spur gear which functions to transmit driving force to a transfer roller of the main assembly when said process cartridge is mounted to the main assembly,   wherein said photosensitive drum is provided at the other end with a helical gear which functions to receive driving force for rotating a developing roller as said process means from the main assembly when said process cartridge is mounted to the main assembly, and also functions to transmit the driving force to the developing roller;   said grounding member functioning to electrically ground said photosensitive drum, and said grounding member including: a base;   a cylinder contacting portion contacted to an inside of said cylinder when said grounding member is mounted to said process cartridge;   a through hole for permitting penetration of said drum shaft when said grounding member is mounted to said process cartridge; and   a drum shaft contact portion having first and second contacting portions for contacting an outer circumferential surface of said drum shaft at longitudinally different positions when said drum shaft is penetrated through said photosensitive drum when said grounding member is mounted to said process cartridge, wherein said first and second contacting portions are each supported by a protruding portion protruding from said base so as to be spaced from a surface of said base, and said first and second contact portions press on the outer circumferential surface of said drum shaft.     
     
     
       33. A member according to claim 32, wherein said first contact portion and said second contact portion are inclined toward an inserting direction of said drum shaft into said photosensitive drum. 
     
     
       34. A member according to claim 32, wherein said first contact portion and said second contact portion are inclined relative to the base of said grounding member, and end portions of said first contact portion and said second contact portion are press-contacted to the outer circumferential surface of said drum shaft. 
     
     
       35. A member according to claim 32, 33 or 34, wherein said cylinder contacting portion has forked end having two branches which are contacted to the cylinder. 
     
     
       36. A member according to claim 32, 33 or 34, wherein said grounding member has a positioning hole, and wherein said grounding member is positioned on the spur gear by engagement between the positioning hole formed in said grounding member and a projection provided on an engaging portion of the spur gear. 
     
     
       37. A member according to claim, 32, 33 or 34, wherein said grounding member is of metal. 
     
     
       38. A member according to claim 37, wherein wherein said metal is phosphor bronze. 
     
     
       39. A grounding member usable for a process cartridge detachably mountable relative to an electrophotographic image forming apparatus, said process cartridge including: a cartridge frame;   an electrophotographic photosensitive drum having a cylinder and a photosensitive layer thereon;   a charging device for charging said photosensitive drum;   a developing member for developing a latent image formed on said photosensitive drum;   a cleaning device for removing residual toner from said photosensitive drum;   a cleaning frame for supporting said photosensitive drum, charging device and cleaning device;   a development frame for supporting said developing member and having a toner accommodating portion for accommodating toner to be used by said developing member, wherein said development frame and said cleaning frame are coupled with each other for relative rotation therebetween; and   a drum shaft for rotatably supporting said photosensitive drum on said cleaning frame, said drum shaft extending through said photosensitive drum,   wherein said photosensitive drum is provided at one longitudinal end with a spur gear which functions to transmit driving force to a transfer roller of the main assembly when said process cartridge is mounted to the main assembly,   wherein said photosensitive drum is provided at the other end with a helical gear which functions to receive driving force for rotating a developing roller as said process means from the main assembly when said process cartridge is mounted to the main assembly, and also functions to transmit the driving force to the developing roller;   said grounding member being of metal and functioning to electrically ground said photosensitive drum, and said grounding member including: a base;   a cylinder contacting portion contacted to an inside of said cylinder when said grounding member is mounted to said process cartridge;   a through hole for permitting penetration of said drum shaft when said grounding member is mounted to said process cartridge; and   a drum shaft contact portion having an inclined portion for contact with said drum shaft in a direction of insertion of said drum shaft into said photosensitive drum when said grounding member is mounted to said process cartridge, wherein said inclined portion has a first bent portion and a second bent portion so as to be contacted at a plurality of positions of the outer circumferential surface of the drum shaft, and the first and second bent portions are each supported by a protruding portion protruding from said base so as to be spaced from a surface of said base, and said first and second bent portions are press-contacted to the outer circumferential surface of the drum shaft at a plurality of positions, wherein said plurality of positions are longitudinally different.     
     
     
       40. A member according to claim 39, wherein said cylinder contacting portion has forked end having two branches which are contacted to the cylinder. 
     
     
       41. A member according to claim 39, wherein said grounding member has positioning hole, and wherein said grounding member is positioned on the spur gear by engagement between the positioning hole formed in said grounding member and a projection provided on an engaging portion of the spur gear. 
     
     
       42. A member according to claim 41, wherein said metal is phosphor bronze. 
     
     
       43. A grounding member usable for a process cartridge detachably mountable relative to an electrophotographic image forming apparatus, said process cartridge including: a cartridge frame;   an electrophotographic photosensitive drum having a cylinder and a photosensitive layer thereon;   a charging device for charging said photosensitive drum;   a developing member for developing a latent image formed on said photosensitive drum;   a cleaning device for removing residual toner from said photosensitive drum;   a cleaning frame for supporting said photosensitive drum, charging device and cleaning device;   a development frame for supporting said developing member and having a toner accommodating portion for accommodating toner to be used by said developing member, wherein said development frame and said cleaning frame are coupled with each other for relative rotation therebetween; and   a drum shaft for rotatably supporting said photosensitive drum on said cleaning frame, said drum shaft extending through said photosensitive drum,   wherein said photosensitive drum is provided at one longitudinal end with a spur gear which functions to transmit driving force to a transfer roller of the main assembly when said process cartridge is mounted to the main assembly,   wherein said photosensitive drum is provided at the other end with a helical gear which functions to receive driving force for rotating a developing roller as said process means from the main assembly when said process cartridge is mounted to the main assembly, and also functions to transmit the driving force to the developing roller;   said grounding member functioning to electrically ground said photosensitive drum, and said grounding member including: a base;   a cylinder contacting portion contacted to an inside of said cylinder when said grounding member is mounted to said process cartridge;   a through hole for permitting penetration of said drum shaft when said grounding member is mounted to said process cartridge; and   a drum shaft contact portion having first and second contact portions for contacting an outer circumferential surface of said drum shaft at longitudinally different positions when said drum shaft is penetrated through said photosensitive drum when said grounding member is mounted to said process cartridge, and wherein said first contact portion and said second contact portion are each supported by a protruding portion protruding from said base so as to be spaced from a surface of said base, and said first and second contact portions are press-contacted to the outer circumferential surface of said drum shaft when said drum shaft is penetrated through said photosensitive drum.     
     
     
       44. A member according to claim 43, wherein said first contact portion and said second contact portion are inclined toward an inserting direction of said drum shaft into said photosensitive drum. 
     
     
       45. A member according to claim 43 or 44, wherein said cylinder contacting portion has forked end having two branches which are contacted to the cylinder. 
     
     
       46. A member according to claim 43 or 44, wherein said grounding member has a positioning hole, and wherein said grounding member is positioned on the spur gear by engagement between the positioning hole formed in said grounding member and a projection provided on an engaging portion of the spur gear. 
     
     
       47. A member according to claim 46, wherein said metal is phosphor bronze. 
     
     
       48. A grounding member usable for a process cartridge detachably mountable relative to an electrophotographic image forming apparatus, said process cartridge including: a cartridge frame;   an electrophotographic photosensitive drum having a cylinder and a photosensitive layer thereon;   a charging device for charging said photosensitive drum;   a developing member for developing a latent image formed on said photosensitive drum;   a cleaning device for removing residual toner from said photosensitive drum;   a cleaning frame for supporting said photosensitive drum, charging device and cleaning device;   a development frame for supporting said developing member and having a toner accommodating portion for accommodating toner to be used by said developing member, wherein said development frame and said cleaning frame are coupled with each other for relative rotation therebetween; and   a drum shaft for rotatably supporting said photosensitive drum on said cleaning frame, said drum shaft extending through said photosensitive drum,   wherein said photosensitive drum is provided at one longitudinal end with a spur gear which functions to transmit driving force to a transfer roller of the main assembly when said process cartridge is mounted to the main assembly,   wherein said photosensitive drum is provided at the other end with a helical gear which functions to receive driving force for rotating a developing roller as said process means from the main assembly when said process cartridge is mounted to the main assembly, and also functions to transmit the driving force to the developing roller;   said grounding member being of metal and functioning to electrically ground said photosensitive drum, and said grounding member including: a base;   a cylinder contacting portion contacted to an inside of said cylinder when said grounding member is mounted to said process cartridge;   a through hole for permitting penetration of said drum shaft when said grounding member is mounted to said process cartridge; and   a drum shaft contact portion having an inclined portion for contact with said drum shaft in a direction of insertion of said drum shaft into said photosensitive drum when said grounding member is mounted to said process cartridge, wherein said inclined portion is supported by a protruding portion protruding from said base so as to be spaced from a surface of said base, and said inclined portion presses on the outer circumferential surface of the drum shaft, and said inclined portion has a first bent portion and a second bent portion so as to be contacted at longitudinally different positions of the outer circumferential surface of the drum shaft when said drum shaft is penetrated through said photosensitive drum.     
     
     
       49. A member according to claim 48, wherein said cylinder contacting portion has forked end having two branches which are contacted to the cylinder. 
     
     
       50. A member according to claim 48 or 49, wherein said grounding member has a positioning hole, and wherein said grounding member is positioned on the spur gear by engagement between the positioning hole formed in said grounding member and a projection provided on an engaging portion of the spur gear. 
     
     
       51. A member according to claim 48, wherein said metal is phosphor bronze. 
     
     
       52. An assembling method for a process cartridge detachably mountable to a main assembly of an image forming apparatus, said process cartridge comprising an electrophotographic photosensitive drum, supported on a drum shaft and having a cylinder and a photosensitive layer thereon, and process means actable on said photosensitive drum, said method comprising the steps of: (a) mounting a grounding member to a longitudinal end portion of said photosensitive drum, wherein said grounding member functions to electrically ground said photosensitive drum, and said grounding member including: a base;   a cylinder contacting portion contacted to an inside of said cylinder;   a through hole for permitting penetration of said drum shaft; and   a drum shaft contact portion having a first contact portion and a second contact portion contacted to an outer circumferential surface of said drum shaft at longitudinally different positions, wherein said first and second contact portions are each supported by a protruding portion protruding from said base so as to be spaced from a surface of said base, and said first and second contact portions press on the outer circumferential surface of said drum shaft;     (b) positioning said photosensitive drum in a cartridge frame of said process cartridge;   (c) inserting said drum shaft, including inserting said drum shaft for rotatably supporting said photosensitive drum on said cartridge frame into a hole formed in a first frame portion of said cartridge frame located adjacent a longitudinal one end of said photosensitive drum from an outside of the first frame portion; then penetrating said drum shaft through said photosensitive drum while expanding the first and second portions; and then inserting said drum shaft into a hole formed in a second frame portion of said cartridge frame located adjacent the other longitudinal end from insert of said second frame portion; wherein one end portion and the other end portion of said drum shaft are supported by said first and second frame portions.   
     
     
       53. A method according to claim 52, wherein said grounding member is mounted on one longitudinal end of aid photosensitive drum by mounting said grounding member on said spur gear, and then mounting said spur gear to one longitudinal end of said photosensitive drum. 
     
     
       54. An assembling method for a process cartridge detachably mountable to a main assembly of an image forming apparatus, said process cartridge comprising an electrophotographic photosensitive drum, supported on a drum shaft and having a cylinder and a photosensitive layer thereon, and process means actable on said photosensitive drum, said method comprising the steps of: (a) mounting a ground member to a longitudinal end portion of said photosensitive drum, wherein said grounding member functions to electrically ground said photosensitive drum, and said grounding member including: a base; and   a drum shaft contact portion having an inclined portion for contact with said drum shaft in a direction of insertion of said drum shaft into said photosensitive drum, wherein said inclined portion has a first bent portion and a second bent portion so as to be contacted at a plurality of positions of the outer circumferential surface of the drum shaft, and the first and second bent portions are each supported by a protruding portion protruding from said base so as to be spaced from a surface of said base, and said first and second bent portions are press-contacted to the outer circumferential surface of the drum shaft at longitudinally different positions when said drum shaft is inserted into said photosensitive drum;     (b) positioning said photosensitive drum in a cartridge frame of said process cartridge;   (c) inserting said drum shaft, including inserting said drum shaft for rotatably supporting said photosensitive drum on said cartridge frame into a hole formed in a first frame portion of said cartridge frame located adjacent a longitudinal one end of said photosensitive drum from an outside of the first frame portion; then penetrating said drum shaft through said photosensitive drum while expanding the first and second bent portions; and then inserting said drum shaft into a hole formed in a second frame portion of said cartridge frame located adjacent the other longitudinal end from inside of said second frame portion; wherein one end portion and the other end portion of said drum shaft are supported by said first and second frame portions, and wherein the first and second bent portions of said grounding member is contacted to the outer circumferential surface of said drum shaft with inclination relative to the drum shaft inserting direction at longitudinally different positions.   
     
     
       55. A method according to claim 54, wherein said grounding member is mounted on one longitudinal end of aid photosensitive drum by mounting said-grounding member on said spur gear, and then mounting said spur gear to one longitudinal end of said photosensitive drum. 
     
     
       56. A grounding member for electrically grounding a photosensitive drum, supported on a drum shaft in a main assembly of an electrophotographic image forming apparatus and having a cylinder, said grounding member comprising: a base;   a cylinder contacting portion contacted to an inside of the cylinder of the photosensitive drum;   a through hole for permitting penetration of the drum shaft for supporting the photosensitive drum; and   a drum shaft contact portion having an inclined portion for contact with an outer circumferential surface of the drum shaft in a direction of insertion of the drum shaft into the photosensitive drum, wherein said inclined portion is supported by a protruding portion protruding from said base so as to be spaced from a surface of said base, and said inclined portion presses on the outer circumferential surface of the drum shaft, wherein said inclined portion has a first bent portion and a second bent portion so as to be contacted at a plurality of positions of the outer circumferential surface of the drum shaft, and the first and second bent portions are contacted to the outer circumferential surface of the drum shaft at longitudinally different positions.   
     
     
       57. A member according to claims 56, wherein said cylinder contacting portion has forked end having two branches which are contacted to the cylinder. 
     
     
       58. A member according to claims 56, wherein said grounding member is of metal. 
     
     
       59. A member according to claim 58, wherein said metal is phosphor bronze.